It will be appreciated that numerous types of sealing arrangements have been previously devised for a slide valve, such as, that shown and disclosed in U.S. Pat. No. 4,491,155. Another previous valve sealing arrangement is shown and disclosed in the published German Patent Application DE OS 14 25 580.
This prior sealing arrangement consisted of a first gasket and a second gasket, which are disposed in coaxial relationship to one another. It will be seen that, situated between the two gaskets, is a connecting member which serves as a support ring for the two gaskets, and which is connected to each of the respective gaskets. The gaskets are connected with the support ring, and are held in the recess of a valve housing by annular retaining elements, which also serve as spacer members. The support ring and the retaining elements are designed and arranged in relation to one another, so that the surfaces of the retaining elements face one another. A portion of their surfaces are in contact, each with one side of the support ring. Thus, the support ring lies between, and is held in place by the retaining elements. The support rings and retaining elements are designed, in relation to their axial extension, so that they can be held in their position by the covers closing the recess of the housing. When this previous known type of arrangement is compared to a sealing arrangement, in which the gaskets are not connected with one another or with the support ring, it has been found to have the advantage that when a part which can move inside the housing, for example, a valve slide, moves past the gasket, no twisting movement is imparted to the gaskets, and they are not torn out of their grooves.
However, with regard to assembly and manufacture, the sealing arrangement has various disadvantages. The individual parts of the sealing arrangement, such as, the gaskets with the support rings and the retaining elements, must be individually-installed in the bore or recess of the housing. The close tolerances and allowances must be complied with, in order to minimize axial play of the sealing arrangement within the recess of the housing boring. The compound parts, such as, the gaskets with the connecting pieces, which serve as support rings, are usually relatively expensive and difficult to manufacture.